Method for the production of a polycarbonate laminate

ABSTRACT

The invention relates to the use of a preparation comprising A) 0.1 to 20 wt % of a binding agent with a polycarbonate derivative based on a geminally disubstituted dihydroxydiphenyl cycloalkane, B) 30 to 99.9 wt % of an organic solvent or of a mixture of solvents, C) 0 to 10 wt %, referred to dry mass, of a dye or of a mixture of dyes, D) 0 to 10 wt % of a functional material or of a mixture of functional materials, E) 0 to 30 wt % of additive and/or auxiliary substances, or of a mixture of such substances, the relative amounts of the components A) to E) always totaling 100 wt %, as an ink jet printing dye.

FIELD OF THE INVENTION

The invention relates to the use of a preparation comprising: A) 0.1 to20 wt % of an organic polymer, B) 30 to 99.9 wt % of a solvent, C) 0 to10 wt %, referred to dry mass, of a dye or of a mixture of dyes, D) 0 to10 wt % of a functional material or of a mixture of functionalmaterials, E) 0 to 30 wt % of additive and/or auxiliary substances, orof a mixture of such substances, the relative amounts of the componentsA) to E) always totaling 100 wt %, as an ink jet printing dye.

The invention further relates to a method for making a structure with anink jet printing layer arranged between two polycarbonate layers, to astructure obtainable by means of such a method, to the use of such amethod for making security and/Or value document, and to a securityand/or value document to be thus made.

BACKGROUND OF THE INVENTION AND PRIOR ART

A preparation to be used use as an ink for ink jet printing is forinstance known from the document EP 1690903 A. Therein, it is an aqueousink for use on a sucking substrate, as for instance letter envelopes. Ifan organic polymer is provided, it does not serve as a binding agent,but as an additive for viscosity adjustment. Such inks cannot be usedfor printing on polycarbonate films for the following reasons explainedwith regard to paper-based security and/or value documents.

A personalization of PC (polycarbonate) based security and/or valuedocuments takes place in the practice by means of the so-called laserengraving method, wherein by optical/thermal interactions of a materialof the security and/or value document with the laser radiation, locallyhighly resolved pyrolysis processes are produced and thus localblackenings due to carbon generation occur. The disadvantage of thismethod is the limitation to black & white or at best gray scalerepresentations.

A colored personalization established for paper-based documents in theink jet printing method is not widely used for PC based security and/orvalue documents up to now. One reason for this is the lackingcompatibility of the used polymers/binders (in connection with the otherink components such as dyes, additives, solvents) with polycarbonate.This applies for instance to the binders known from the documentsUllmann's Encyclopedia of Industrial Chemistry, Electronic Release 2007,Wiley Verlag, chapter “Imaging Technology, Ink-Jet Inks, and Ullmann'sEncyclopedia of Industrial Chemistry, Electronic Release 2007, WileyVerlag, chapter “Paints and Coatings”, such as nitrocellulose, celluloseester (cellulose acetate butyrate, CAB), polyacrylates, polyesters,epoxides etc. Secondly, PC films imprinted with such inks cannot easilybe laminated. PC films imprinted over the full surface practicallycannot be laminated at all, for the dye layer represents a barrierlayer. In the event of an only partial printing process, there is therisk of a local delamination. Thirdly, polycarbonate is no sucking base.Common inks for ink jet printing are adjusted to good absorption timeson paper and when imprinted on a non-sucking PC film they remain on thesurface and can even after drying often completely be removed withoutresidues, since the color does not penetrate into the material.Fourthly, ink jet printing layers made from insofar known inks lacktemperature stability. Since in the field of security and/or valuedocuments, imprinted PC films are typically laminated to each otherunder the action of pressure (>2 bars) and temperature (>160° C.), thereis a risk of discoloration of the ink jet printing layer.

From the document EP 0 688 839 B1, silk-screen printing inks based ondisubstituted dihydroxydiphenyl cycloalkanes are known. From thisdocument can also be taken methods for making such polycarbonates. Thisdocument with its complete contents is hereby included in the scope ofdisclosure of the present application. Normally silk-screen printinginks can however not easily be used for ink jet printing, since ink jetprinting poses special requirements for the used inks because of thenozzle technology of the printing heads.

Technical Object of the Invention

It is therefore the technical object of the invention to provide means,which permit the application of ink jet printing for making a securityand/or value document based on polycarbonate polymer layers and provideink jet printing layers on such layers, which satisfy all opticalrequirements, may in particular also be colored, wherein during alamination the optical properties are not impaired, and which do not actas an barrier layer during the lamination, but rather even contribute tothe formation of a monolithic structure from the polymer layers.

Basics of the Invention and Preferred Embodiments

For achieving this technical object, the invention teaches the use of apreparation comprising: A) 0.1 to 20 wt % of a binding agent with apolycarbonate derivative based on a geminally disubstituteddihydroxydiphenyl cycloalkane, B) 30 to 99.9 wt % of a preferablyorganic solvent or of a mixture of solvents, C) 0 to 10 wt %, referredto dry mass, of a dye or of a mixture of dyes, D) 0 to 10 wt % of afunctional material or of a mixture of functional materials, E) 0 to 30wt % of additive and/or auxiliary substances, or of a mixture of suchsubstances, the relative amounts of the components A) to E) alwaystotaling 100 wt %, as an ink jet printing dye.

First of all, the invention is based on the finding that polycarbonatederivatives used according to the invention are highly compatible withpolycarbonate materials for films, in particular with polycarbonatesbased on bisphenol A, such as for instance Makrofol® films. The highcompatibility is shown by that the ink jet printing layer providedaccording to the invention with a polycarbonate derivative combines withthe polycarbonate materials of the films to form a monolithic structure.A layer boundary between the materials cannot optically be detectedanymore after the lamination. Further, the used polycarbonate derivativeis stable at high temperatures and does not show any discolorations attemperatures up to 200° C. and more being typical for a lamination.Furthermore, it is surprising that an ink composition known forsilk-screen printing (under adjustment of the viscosity) is alsosuitable, with regard to the used binder, for ink jet printing. Finallyit was found to be an advantageous property that the dye of thecomposition penetrates into the imprinted polymer layer, so that aprinting layer applied on the surface of the polymer layer cannot beremoved in a non-destructive manner. Thus, compositions used accordingto the invention are also suitable e.g. for the surface personalizationof security and/or value documents, since when printing on the polymerlayer, an integral structure is formed.

As a result, the invention achieves that a security and/or valuedocument based on polycarbonate films can be provided with a coloredoverprint, for instance during the personalization as a passportphotograph, wherein the ink jet printing layer does not only not act asa barrier layer, but rather even more promotes the formation of amonolithic structure during the lamination. The structure fulfills withregard to integrity and durability all requirements.

In detail, the polycarbonate derivative may contain functional carbonatestructure units of formula (I),

wherein R¹ and R² are independently from each other hydrogen, halogen,preferably chlorine or bromine, C₁-C₈ alkyl, C₅-C₆ cycloalkyl, C₆-C₁₀aryl, preferred phenyl, and C₇-C₁₂ aralkyl, preferably phenyl-C₁-C₄alkyl, in particular benzyl; m is an integer from 4 to 7, preferably 4or 5; R³ and R⁴ can be individually selected for each X, andindependently represent hydrogen or C₁-C₆ alkyl; X is carbon and n aninteger greater than 20, with the proviso that at at least one atom X,R³ and R⁴ are both alkyl.

It is preferred, if at 1 to 2 atoms X, in particular at one atom X only,R³ and R⁴ both are alkyl. R³ and R⁴ may in particular be methyl. The Xatoms in the alpha position to the diphenyl-substituted C atom (C1)cannot be dialkyl-substituted. The X atoms in the beta position to C1can be disubstituted with alkyl. Preferred is m=4 or 5. Thepolycarbonate derivative may for instance be formed on the basis ofmonomers, such as 4,4′-(3,3,5-trimethyl cyclohexane-1,1-diyl)diphenol,4,4′-(3,3-dimethyl cyclohexane-1,1-diyl)diphenol, or4,4′-(2,4,4-trimethyl cyclopentane-1,1-diyl)diphenol.

A polycarbonate derivative used according to the invention may forinstance be made from diphenols of formula (Ia) according to thedocument DE 38 32 396.6, the scope of disclosure of which with itscomplete contents is hereby included in the scope of disclosure of thisdescription.

A diphenol of formula (Ia) under formation of homopolycarbonates as wellas several diphenols of formula (Ia) under formation of copolycarbonatescan be used (the meaning of radicals, groups and parameters same as informula I).

Furthermore, the diphenols of formula (Ia) can also be used in a mixturewith other diphenols, for instance with those of formula (Ib)

HO—Z—OH  (Ib),

for making high-molecular, thermoplastic, aromatic polycarbonatederivatives.

Suitable other diphenols of formula (Ib) are those, wherein Z is anaromatic radical with 6 tc 30 C atoms, which may contain one or severalaromatic nuclei, be substituted and contain aliphatic radicals or othercycloaliphatic radicals than those of formula (Ia) or heteroatoms asbridge members.

Examples for the diphenols of formula (Ib) are: hydroquinone, resorcin,dihydroxydiphenyls, bi-(hydroxyphenyl)-alkanes,bis-(hydroxyphenyl)-cycloalkanes, bis-(hydroxyphenyl)-sulfides,bis-(hydroxyphenyl)-ethers, bis-(hydroxyphenyl)-ketones,bis-(hydroxyphenyl)-sulfones, bis-(hydroxyphenyl)-sulfoxides,alpha,alpha′-bis-(hydroxyphenyl)-diisopropylbenzenes and theirnuclear-alkylated and nuclear-halogenated compounds.

These and other suitable diphenols are e.g. described in the documentsU.S. Pat. Nos. 3,028,365, 2,999,835, 3,148,172, 3,275,601, 2,991,273,3,271,367, 3,062,781, 2,970,131 and 2,999,846, in the documents DE-A 1570 703, 2 063 050, 2 063 052, 2 211 956, the FR-A 1 561 518 and in themonograph “H. Schnell, Chemistry and Physics of Polycarbonates,Interscience Publishers, New York 1964”, which with its completecontents is hereby included in the scope of disclosure of the presentapplication.

Preferred other diphenols are for instance: 4,4′-dihydroxydiphenyl,2,2-bis-(4-hydroxyphenyl)-propane,2,4-bis-(4-hydroxyphenyl)-2-methylbutane,1,1-bis-(4-hydroxyphenyi)-cyclohexane,alpha,alpha-bis-(4-hydroxyphenyl)-p-diisopropylbenzene,2,2-bis-(3-methyl-4-hydroxyphenyl)-propane,2,2-bis-(3-chloro-4-hydroxyphenyl)-propane,bis-(3,5-dimethyl-4-hydroxyphenyl)-methane,2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane,bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfone,2,4-bis-(3,5-dimethyl-4-hydroxyphenyl)-2-methylbutane,1,1-bis-(3,5-dimethyl-4-hydroxyphenyl)-cyclohexane,alpha,alpha-bis-(3,5-dimethyl-4-hydroxyphenyl)-p-diisopropylbenzene,2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane and2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane.

Particularly preferred diphenols of formula (Ib) are for instance:2,2-bis-(4-hydroxyphenyl)-propane,2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane,2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane,2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane and1,1-bis-(4-hydroxyphenyl)-cyclohexane. In particular2,2-bis-(4-hydroxyphenyl)-propane is preferred. The other diphenols maybe used individually as well as in a mixture.

The molar ratio of diphenols of formula (Ia) to, if applicable, the alsoused other diphenols of formula (Ib) should be between 100 mol % (Ia) to0 mol % (Ib) and 2 mol % (Ia) to 98 mol % (Ib), preferably between 100mol % (Ia) to 0 mol % (Ib) and 10 mol % (Ia) to 90 mol % (Ib) and inparticular between 100 mol % (Ia) to 0 mol % (Ib) and 30 mol % (Ia) to70 mol % (Ib).

The high-molecular polycarbonate derivatives from the diphenols offormula (Ia), if applicable, in combination with other diphenols, may bemade according to the known polycarbonate production methods. Thedifferent diphenols may be linked in a statistical manner as well asalso block-wise.

The polycarbonate derivatives used according to the invention may bebranched in a per se known manner. If the branching is desired, this canbe achieved in a per se known manner by condensation of small amounts,preferably amounts between 0.05 and 2.0 mol % (referred to the useddiphenols), at three or more than three-functional compounds, inparticular such with three or more than three phenolic hydroxyl groups.Some branching agents with three or more than three phenolic hydroxylgroups are: phloroglucin,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene-2,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane,1,3,5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)-ethane,tri-(4-hydroxyphenyl)-phenylmethane,2,2-bis-[4,4-bis-(4-hydroxyphenyl)-cyclohexyl]-propane,2,4-bis-(4-hydroxyphenyl-isopropyl)-phenol,2,6-is-(2-hydroxy-5-methyl-benzyl)-4-methylphenol,2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane,hexa-[4-(4-hydroxyphenyl-isopropyl)-phenyl]-orthoterephthalic acidester, tetra-(4-hydroxyphenyl)-methane,tetra-(4-(4-hydroxyphenyl-isopropyl)phenoxy)-methane and1,4bis-(4′,4″-dihydroxytriphenyl)-methyl)-benzene. Some of the otherthree-functional compounds are 2,4-dihydroxy benzoic acid, trimesicacid, cyanuric chloride and3,3-bis-(3-methyl-4-hydroxyphenyl)-2-oxo-2,3-dihydroindol.

As chain stoppers for the per se known control of the molecular weightof the polycarbonate derivatives are used monofunctional compounds inusual concentrations. Suitable compounds are e.g. phenol,tert-butylphenols or other alkyl-substituted phenols. For controllingthe molecular weight, in particular small amounts of phenols of formula(Ic) are suitable

wherein R is a branched C8 and/or C9-alkyl radical.

Preferably the share of CH₃ protons in the alkyl radical R is between 47and 89% and the share of the CH and CH₂ protons is between 53 and 11%;also preferably R is in an o and/or p position to the OH group, andparticularly preferably the upper limit of the ortho share is 20%. Thechain stoppers are used in general in amounts from 0.5 to 10, preferably1.5 to 8 mol %, referred to the used diphenols.

The polycarbonate derivatives may preferably be made according to thephase boundary method (cf. H. Schnell Chemistry and Physics ofPolycarbonates, Polymer Reviews, Vol. IX, page 33ff., Interscience Publ.1964) in a per se known manner.

Herein, the diphenols of formula (Ia) are dissolved in an aqueousalkaline phase. For making copolycarbonates with other diphenols,mixtures of diphenols of formula (Ia) and the other diphenols, forinstance those of formula (Ib), are used. For controlling the molecularweight, chain stoppers e.g. of formula (Ic) may be added. Then areaction is performed in presence of an inert, preferablypolycarbonate-dissolving, organic phase with phosgene according to themethod of the phase boundary condensation. The reaction temperature isbetween 0° C. and 40° C.

The, if applicable, also used branching agents (preferably 0.05 to 2.0mol %) may either be presented with the diphenols in the aqueousalkaline phase or be added dissolved in the organic solvent before thephosgenation. Beside the diphenols of formula (Ia) and, if applicable,other diphenols (Ib), thus their mono and/or bis-chlorocarbonic acidesters can also be used, the latter being added dissolved in organicsolvents. The amount of chain stoppers and of branching agents thendepends on the molar amount of diphenolate radicals corresponding toformula (Ia) and, if applicable, formula (Ib); when chlorocarbonic acidesters are also used, the amount of phosgene can correspondingly bereduced in a known manner.

Suitable organic solvents for the chain stoppers and, if applicable, forthe branching agents and the chlorocarbonic acid esters are for instancemethylene chloride, chlorobenzene and in particular mixtures ofmethylene chloride and chlorobenzene. If applicable, the used chainstoppers and branching agents can be dissolved in the same solvent.

As an organic phase for the phase boundary polycondensation serve forinstance methylene chloride, chlorobenzene and mixtures of methylenechloride and chlorobenzene.

As an aqueous alkaline phase serves for instance a NaOH solution. Makingthe polycarbonate derivatives according to the phase boundary method canby catalyzed in a usual manner by catalyzers such as tertiary amines, inparticular tertiary aliphatic amines such as tributylamine ortriethylamine; the catalyzers can be used in amounts from 0.05 to 10 mol%, referred to the moles of used diphenols. The catalyzers can be addedbefore the phosgenation or during or also after the phosgenation.

The polycarbonate derivatives can be made according to the known methodin a homogeneous phase, the so-called “pyridine method” and according tothe known method for the transesterification of molten mass by using forinstance diphenyl carbonate instead of phosgene.

The polycarbonate derivatives may be linear or branched, they arehomopolycarbonates or copolycarbonates based on the diphenols of formula(Ia).

By the arbitrary composition with other diphenols, in particular withthose of formula (Ib), the polycarbonate properties can be varied in afavorable manner. In such copolycarbonates, the diphenols of formula(Ia) are contained in polycarbonate derivatives in amounts from 100 mol% to 2 mol %, preferably in amounts from 100 mol % to 10 mol % and inparticular in amounts from 100 mol % to 30 mol %, referred to the totalamount of 100 mol % of diphenol units.

A particularly advantageous embodiment of the invention is characterizedby that the polycarbonate derivative comprises a copolymer in particularconsisting of monomer units M1 based on formula (Ib), preferablybisphenol A, and monomer units M2 based on the geminally disubstituteddihydroxydiphenyl cycloalkane, preferably of the 4,4′-(3,3,5-trimethylcyclohexane-1,1-diyl)diphenol, wherein the molar ratio M2/M1 ispreferably greater than 0.3, in particular greater than 0.4, forinstance greater than 0.5. For such copolymers it has namely been foundthat surprisingly the glass temperature Tg below 150° C. after a firstheating cycle may be increased in a second heating cycle, which cansubstantially improve the stability of the obtained structure.

It is preferred, if the polycarbonate derivative has an averagemolecular weight (mean weight) of at least 10,000, preferably of 20,000to 300,000.

The component B may in principle be substantially organic or aqueous.Substantially aqueous means that up to 20 wt % of the component B can beorganic solvents. Substantially organic means that up to 5 wt % watermay be present in the component B. Preferably the component B comprisesor consists of a liquid aliphatic, cycloaliphatic, and/or aromatichydrocarbon, a liquid organic ester, and/or of a mixture of suchsubstances. The used organic solvents are preferably halogen-freeorganic solvents. These may in particular be aliphatic, cycloaliphatic,aromatic hydrocarbons, such as mesitylene, 1,2,4-trimethylbenzene,cumene and solvent naphtha, toluene, xylene; (organic) esters, such asmethylacetate, ethylacetate, butylacetate, methoxypropylacetate,ethyl-3-ethoxypropionate. Preferred are mesitylene,1,2,4-trimethylbenzene, cumene and solvent naphtha, toluene, xylene,acetic acid methyl ester, acetic acid ethyl ester methoxypropylacetate,ethyl-3-ethoxypropionate. Particularly preferred are: mesitylene(1,3,5-trimethylbenzene), 1,2,4-trimethylbenzene, cumene(2-phenylpropane), solvent naphtha and ethyl-3-ethoxypropionate.

A suitable mixture of solvents comprises for instance L1) 0 to 10 wt %,preferably 1 to 5 wt %, in particular 2 to 3 wt %, of mesitylene, L2) 10to 50 wt %, preferably 25 to 50 wt %, in particular 30 to 40 wt %, of1-methoxy-2-propanol-acetate, L3) 0 to 20 wt %, preferably 1 to 20 wt %,in particular 7 to 15 wt %, of 1,2,4-trimethylbenzene, L4) 10 to 50 wt%, preferably 25 to 50 wt %, in particular 30 to 40 wt %, ofethyl-3-ethoxypropionate, L5) 0 to 10 wt %, preferably 0.01 to 2 wt %,in particular 0.05 to 0.5 wt %, of cumene, and L6) 0 to 80 wt %,preferably 1 to 40 wt %, in particular 15 to 25 wt %, of solventnaphtha, the relative amounts of the components L1 to L6 always totaling100 wt %.

Typically the first polycarbonate layer and the second polycarbonatelayer have a glass temperature Tg of more than 145° C., in particularmore than 147° C.

The polycarbonate derivative typically has an average molecular weight(mean weight) of at least 10,000, preferably from 20,000 to 300,000.

The preparation may comprise in detail: A) 0.1 to 10 wt %, in particular0.5 to 5 wt %, of a binding agent with a polycarbonate derivative basedon a geminally disubstituted dihydroxydiphenyl cycloalkane, B) 40 to99.9 wt %, in particular 45 to 99.5 wt %, of an organic solvent or of amixture of solvents, C) 0.1 to 6 wt %, in particular 0.5 to 4 wt %, of adye or of a mixture of dyes, D) 0.001 to 6 wt %, in particular 0.1 to 4wt %, of a functional material or of a mixture of functional materials,E) 0.1 to 30 wt %, in particular 1 to 20 wt %, of additive and/orauxiliary substances, or of a mixture of such substances.

If a dye should be provided, in principle any dye or mixture of dyes canbe used as a component C. Dyes are all coloring substances. This means,they may be dyes (a survey of dyes is given in Ullmann's Encyclopedia ofIndustrial Chemistry, Electronic Release 2007, Wiley Verlag, chapter“Dyes, General Survey”), as well as pigments (a survey of organic andinorganic pigments is given in Ullmann's Encyclopedia of IndustrialChemistry, Electronic Release 2007, Wiley Verlag, chapter “Pigments,Organic” and “Pigments, Inorganic”). Dyes should be soluble or (stably)dispersible or suspensible in the solvents of the component B.Furthermore, it is advantageous, if the dye is stable, in particularcolor-stable at temperatures of 160° C. and more for a period of morethan 5 min. It is also possible that the dye is subjected to a given andreproducible color change under the processing conditions and isselected correspondingly. Pigments must be present, in addition to thetemperature stability, in particular in a finest particle sizedistribution. In the practice of ink jet printing this means that theparticle size should not exceed 1.0 μm, since otherwise occlusions inthe printing head will result. Normally, nano-scale solid pigments haveproven themselves.

The dyes may be kationic, anionic or also neutral. Examples for dyesused in ink jet printing are: Brillantschwarz C.I. .Nr. 28440,Chromogenschwarz C.I. Nr. 14645, Direkttiefschwarz E C.I. Nr. 30235,Echtschwarzsalz B C.I. Nr. 37245, Echtschwarzsalz K C.I. Nr. 37190,Sudanschwarz H B C.I. 26150, Naphtolschwarz C.I. Nr. 20470, Bayscript®Schwarz Flüssig, C.I. Basic Black 11, C.I. Basic Blue 154, Cartasol®Türkis K-ZL Flüssig, Cartasol® Türkis K-RL Flüssig (C.I. Basic Blue140), Cartasol Blau K5R Flüssig. Suitable are further e.g. thecommercially obtainable dyes Hostafine® Schwarz T S Flüssig (sold byClariant GmbH Germany), Bayscript® Schwarz Flüssig (C.I., mixture, soldby Bayer AG Germany), Cartasol® Schwarz M G Flüssig (C.I. Basic Black11, registered trademark of Clariant GmbH Germany), Flexonylschwarz® PR100 (E C.I. Nr. 30235, sold by Hoechst AG), Rhodamin B, Cartasol® OrangeK3 GL, Cartasol® Gelb K4 GL, Cartasol® K GL, or Cartasol® Rot K-3B.Further, as soluble dyes can be used anthraquinone, azo, quinophthalone,cumarin, methin, perinone, and/or pyrazole dyes, e.g. obtainable underthe trade name Macrolex®. Further suitable dyes are described in thedocument Ullmann's Encyclopedia of Industrial Chemistry, ElectronicRelease 2007, Wiley Verlag, chapter “Colorants Used in Ink Jet Inks”.Well soluble dyes will lead to an optimum integration in the matrix orthe binder of the printing layer. The dyes can be added either directlyas a dye or pigment or as a paste, a mixture of dye and pigment togetherwith an additional binder. This additional binder may be different froma binder according to the invention (e.g. may be a polyester), shouldhowever be chemically compatible with the additional components of thepreparation used according to the invention. If such a paste is used asa dye, the amount of the component B refers to the dye without the othercomponents of the paste. These other components of the paste must thenbe subsumed under the component E. When using so-called colored pigmentsin the scale colors cyan-magenta-yellow and preferably also (soot-)black, full-tone color images are possible.

The component D comprises substances, which by using technical means canimmediately be seen by the human eye or by using suitable detectors.These are materials familiar to the man skilled in the art (cf. also vanRenesse, Optical Document Security, 3rd ed., Artech House, 2005), whichare used for the protection of value and security documents. Theretobelong luminescent substances (dyes or pigments, organic or inorganic)such as e.g. photoluminophores, electroluminophores, anti-Stokesluminophores, fluorophores, but also magnetizable, photo-acousticallyaddressable or piezoelectric materials. Furthermore, Raman-active orRaman-amplifying materials can be used, same as so-called barcodematerials. Here, too, the preferred criteria are either the solubilityin the component B or for pigmented systems particle sizes <1 μm andtemperature stability for temperatures >160° C. in the meaning of theexplanations with regard to the component C. Functional materials candirectly be added or via a paste, i.e. mixture with an additionalbinder, which is then a constituent of the component E, or the binder ofthe component A used according to the invention.

The component E comprises the substances normally used for inks in inkjet printing, such as anti-foam agents, set-up agents, wetting agents,tensides, floating agents, drying agents, catalyzers, (light)stabilizers, preservation agents, biocides, tensides, organic polymersfor viscosity adjustment, buffer systems, etc. Set-up agents are forinstance conventional set-up salts. An example is sodium lactate. Asbiocides may be used all commercially available preservation agents,which are used for inks. Examples are Proxel®GXL and Parmetol® A26.Tensides may be all commercially available tensides, which are used forinks. Preferred are amphoteric or non-ionic tensides. Of course,however, the use of special anionic or cationic tensides, which do notalter the properties of the dye, is also possible. Examples for suitabletensides are betaines, ethoxilated diols etc. Examples are the productseries Surfynol® and Tergitol®. The amount of tensides is for instanceselected such that the surface tension of the ink is in the range from10 to 60 mN/m, preferably from 25 to 45 mN/m, measured at 25° C. Abuffer system may be provided, which stabilizes the pH value in therange from 2.5 to 8.5, in particular in the range from 5 to 8. Suitablebuffer systems are lithium acetate, borate buffer, triethanolamine oracetic acid/sodium acetate. A buffer system will in particular beapplied in the case of a substantially aqueous component B. Foradjusting the viscosity of the ink, (if applicable) water-solublepolymers may be provided. These may be all polymers being suitable forconventional ink formulations. Examples are water-soluble starch, inparticular with an average molecular weight from 3,000 to 7,000,polyvinylpyrolidone, in particular with an average molecular weight from25,000 to 250,000, polyvinyl alcohol, in particular with an averagemolecular weight from 10,000 to 20,000, xanthan gum, carboxymethylcellulose, ethylene oxide/propylene oxide block copolymer, in particularwith an average molecular weight from 1,000 to 8,000. An example for theabove block copolymer is the product series Pluronic®. The share ofbiocide, referred to the total amount of ink, may be in the range from 0to 0.5 wt %, preferably from 0.1 to 0.3 wt %. The share of tenside,referred to the total amount of ink, may be in the range from 0 to 0.2wt %. The share of set-up agents, referred to the total amount of ink,may be from 0 to 1 wt %, preferably from 0.1 to 0.5 wt %.

To the auxiliary agents also belong all other components, such as forinstance acetic acid, formic acid or n-methyl pyrolidone or otherpolymers from the used dye solution or paste.

With regard to substances, which are suitable as component E, referenceis made for instance to Ullmann's Encyclopedia of Chemical Industry,Electronic Release 2007, Wiley Verlag, chapter “Paints and Coatings”,section “Paint Additives”.

The invention further relates to a method for making a structure with atleast one first polymer layer and, optionally, a second polymer layer,each made from a polycarbonate polymer based on bisphenol A, wherein onthe first polymer layer an ink jet printing layer is arranged,comprising the following steps: a) on at least one partial region of thefirst polymer layer, the ink jet printing layer from a preparation usedaccording to the invention is applied, b) optionally, the ink jetprinting layer is dried, c) optionally after step a) or step b), thesecond polymer layer is placed on the first polymer layer, covering theink jet printing layer, and the first polymer layer and the secondpolymer layer are laminated with each other under pressure, at atemperature from 120° C. to 230° C. and for a defined time.

In other words, a structure according to the invention may only consistof a polymer layer and of a printing layer applied by means of thepreparation used according to the invention, may however also compriseanother polymer layer, if applicable, in another structure withadditional layers. It is for instance possible that the printing layeris provided as the uppermost layer within a structure (if applicable,with additional layers). Further, the printing layer can be imprinteddirectly and without another cover on a polymer layer adapted as anoverlay film.

The ink jet printing layer may be provided over the full surface on thefirst polymer layer. In most cases, however, the ink jet printing layerwill be provided in a partial region only of the surface of the firstpolymer layer.

The specific pressure (pressure directly at the workpiece) in step d) istypically in the range from 1 bar to 10 bars, in particular in the rangefrom 3 bars to 7 bars. The temperature in step d) is preferably in therange from 140° C. to 200° C., in particular in the range from 150° C.to 180° C. The time of the step d) may be in the range from 0.5 s to 120s, in particular from 5 s to 60 s.

In step b), drying can be performed at a temperature in the range from20° C. to 120° C., in particular from 20° C. to 80° C., preferably from20° C. to 60° C., for a time of at least 1 s, preferably from 5 s to6,000 s.

The first polycarbonate layer and the second polycarbonate layer may,independently from each other, have a glass temperature Tg of more than145° C.

The thickness of the first polycarbonate layer and of the secondpolycarbonate layer may be, identical or different, in the range from 10to 1,000 μm, in particular from 20 to 200 μm.

The thickness, measured in directions orthogonal to a main face of apolycarbonate layer, of the ink jet printing layer may be, before orafter drying, in the range from 0.01 to 10 μm, in particular from 0.05to 5 μm, preferably from 0.02 to 1 μm.

Subject matter of the invention is also a structure obtainable with amethod according to the invention. Such a structure typically containsat least one first polycarbonate layer and a second polycarbonate layerand an ink jet printing layer from a preparation used according to theinvention and arranged between the first polycarbonate layer and thesecond polycarbonate layer.

A method according to the invention for making a structure may be usedfor making a security and/or value document, wherein optionallysimultaneously with, before or after the production of the structure,the first polycarbonate layer and/or the second polycarbonate layer aredirectly or indirectly connected in a stack with at least one additionallayer, for instance a carrier layer.

Examples for security and/or value documents are: identity cards,passports, ID cards, access control cards, visas, tax symbols, tickets,driver's licenses, vehicle documents, banknotes, checks, postage stamps,credit cards, any chip cards and adhesive labels (e.g. for productprotection). Such security and/or value documents typically comprise atleast one substrate, a printing layer and optionally a transparent coverlayer. Substrate and cover layer themselves may be composed of amultitude of layers. A substrate is a carrier structure, onto which theprinting layer with information, images, patterns and the like isapplied. As materials for a substrate, all conventional materials on apaper and/or (organic) polymer basis can be used. Such a security and/orvalue document comprises within the total multi-layer structure astructure according to the invention. Beside the structure according tothe invention, at least one (additional) printing layer may be provided,which may be applied on an external surface of the structure or on anadditional layer connected with the structure.

Finally, the invention relates to a security and/or value document to bethus made or comprising a structure according to the invention.

The invention can however also be used in other technical fields.Abrasion-resistant decorations of injection-molded parts can be made byin-mold lamination of films. According to prior art, PC films areimprinted by silk-screen printing, plastically deformed (e.g.deep-drawing), placed in an injection mold and in-mold laminated with athermoplastic material. In this way, e.g. casings for mobile phones ordecorative housings are made. Multi-colored decorations require theproduction of several printing forms/printing screens and are thereforeonly economical for high quantities. With an ink used according to theinvention, however, also piece productions or unique motives arepossible, and thus e.g. individualized, highly abrasion-resistantcasings for mobile phones (for example with a photograph) orpersonalized tachometer discs (e.g. initials of the owner) can beproduced.

Therefore, the invention also relates to a method for making a structurewith at least one polymer layer and an injection-molded part from apolymer material, wherein between the polymer layer and theinjection-molded part an ink jet printing layer is arranged, comprisingthe following steps: a) on at least one partial region of the polymerlayer, the ink jet printing layer from a preparation used according tothe invention is applied, b) optionally, the ink jet printing layer isdried, c) after step a) or step b), the polymer layer is placed in aninjection mold (if necessary after plastic deformation of the imprintedpolymer layer for fitting to the walls of the injection mold), the inkjet printing layer showing toward inside, d) into the injection mold,the polymer material is injected at a temperature of at least 60° C.,and e) after cooling-off to a temperature of at least 20° C. below thetemperature of the step d), the structure is taken from the injectionmold.

The polymer layer may preferably be a polycarbonate layer based onbisphenol A. As polymer materials, in principle all thermoplasticpolymers usual in the field of plastic injection can be used.

The temperature in step d) may be in the range from 80° C. to 200° C.,in particular in the range from 100° C. to 180° C. The temperature instep e) may be at least 40° C. below the temperature in step d).

In principle, otherwise all explanations given in the context with astructure for a security and/or value document will apply in ananalogous manner.

Therefore, the invention also comprises a structure comprising at leastone polycarbonate layer and an injection-molded part and an ink jetprinting layer from a preparation used according to the invention andarranged between the polycarbonate layer and the injection-molded part.

In the following, the invention is described in more detail withreference to non-limiting embodiments. There are:

FIG. 1: a representation of a test print area, and

FIG. 2: details of a portrait of a person made by a method according tothe invention.

EXAMPLE 1 Making Polycarbonate Derivatives to be used According to theInvention EXAMPLE 1.1 Making a First Polycarbonate Derivative

205.7 g (0.90 mole) bisphenol A (2,2-bis-(4-hydroxyphenyl)-propane, 30.7g (0.10 mole) 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane,336.6 g (6 mole) KOH and 2,700 g water are dissolved in an inert gasatmosphere under stirring. Then a solution of 1.88 g phenol in 2,500 mlmethylene chloride is added. Into the well stirred solution, 198 g (2mole) phosgene are introduced at pH 13 to 14 and 21 to 25° C. Then 1 mlethylpiperidine is added and stirred for another 45 min. Thebisphenolate-free aqueous phase is separated, after acidification withphosphoric acid, the organic phase is washed neutrally with water andfreed from solvent.

The polycarbonate derivative had a relative solution viscosity of 1.255.The glass temperature was determined to be 157° C. (DSC).

EXAMPLE 1.2 Making a Second Polycarbonate Derivative

In an analogous manner to Example 1, a mixture of 181.4 g (0.79 mole)bisphenol A and 63.7 g (0.21 mole)1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane, was reacted tothe polycarbonate derivative.

The polycarbonate derivative has a relative solution viscosity of 1.263.The glass temperature was determined to be 167° C. (DSC).

EXAMPLE 1.3 Making a Third Polycarbonate Derivative

In an analogous manner to Example 1, a mixture of 149.0 g (0.65 mole)bisphenol A (2,2-n bis-(4-hydroxyphenyl)-propane and 107.9 g (0.35 mole)1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane was reacted to thepolycarbonate derivative.

The polycarbonate derivative had a relative solution viscosity of 1.263.The glass temperature was determined to be 183° C. (DSC).

EXAMPLE 1.4 Making a Fourth Polycarbonate Derivative

In an analogous manner to Example 1, a mixture of 91.6 g (0.40 mole)bisphenol A and 185.9 g (0.60 mole)1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane was reacted to thepolycarbonate derivative.

The polycarbonate derivative had a relative solution viscosity of 1.251.The glass temperature was determined to be 204° C. (DSC).

EXAMPLE 1.5 Making a Fifth Polycarbonate Derivative

As in Example 1, a mixture of 44.2 g (0.19 mole) bisphenol A and 250.4 g(0.81 mole) 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane wasreacted to the polycarbonate.

The polycarbonate derivative had a relative solution viscosity of 1.248.The glass temperature was determined to be 216° C. (DSC).

EXAMPLE 2 Making a Liquid Preparation being Suitable for Making an InkJet Printing Dye

A liquid preparation was made from 17.5 weight parts of thepolycarbonate derivative from Example 1.3 and 82.5 weight parts of asolvent mixture according to Table I.

TABLE I Mesitylene 2.4 1-methoxy-2-propanolacetate 34.951,2,4-trimethylbenzene 10.75 Ethyl-3-ethoxypropionate 33.35 Cumol 0.105Solvent naphtha 18.45

A colorless, highly viscous solution with a solution viscosity of 800mPa·s at ambient temperature was obtained.

EXAMPLE 3 Making a First Ink Jet Printing Dye used According to theInvention

In a 50 mL wide-neck thread glass, 4 g polycarbonate solution of Example2 and 30 g of the mixture of solvents of Example 2 were homogenized witha magnetic stirrer. A colorless, low-viscous solution with a solutionviscosity of 1.67 mPa·s at ambient temperature was obtained.

The surface tension of this basic ink was determined with an OEGSurftens measuring system according to the pendant drop method to be21.4±1,9 mN/m.

An addition of a pigment or of a dye was not made, since this ink onlyserved for use in the test print of Example 6.

EXAMPLE 4 Making a Second Ink Jet Printing Dye used According to theInvention

In an analogous manner to Example 3, 10 g polycarbonate solution ofExample 2 and 32.5 g mixture of solvents of Example 2 were homogenizedwith a magnetic stirrer (4% PC solution). A colorless, low-viscoussolution with solution viscosity of 5.02 mPa·s at 20° C. was obtained.Here, too, no addition of a pigment or dye was made, since this ink onlyserved for use in the test print of Example 7.

EXAMPLE 5 Making a Third Ink Jet Printing Dye used According to theInvention

A polycarbonate solution according to Example 4 was prepared andadditionally reacted with approx. 2% pigment Black 28. An ink results,by means of which black & white images can be printed on polycarbonatefilms, and reference is made to Example 8.

EXAMPLE 6 Drop Size when Printing with an Ink According to Example 3

The solution of Example 3 was transferred by filtration into a printercartridge and printed with an ink jet printer FUJIFILM-Dimatix DMP 2800under variation of various printing parameters. The used printer is aso-called drop-on-demand system, wherein the drop generation is made bya piezoelectric printing head. The DMP 2800 has a stroboscopic imagerecording system, by means of which the drop formation and the drop pathcan be investigated. The prints were dried at 100° C. for 30 min.Depending on the base, different drop sizes can be achieved, as is shownin Table 1.

TABLE 1 Polycarbonate Velin Substrate Glass (smooth) paper Ø individual~74 μm ~85 μm ~100 μm drops

As expected, on sucking bases, the drops will be absorbed more than onnon-sucking bases such as glass or plastic.

EXAMPLE 7 Determination of the Layer Thickness of an Ink Jet PrintingLayer

An ink according to Example 4 was printed on glass substrates. Theso-called drop distance (pitch, see also FIG. 1) varied from 10 to 45μm. The prints were again dried at 100° C. for 30 min. Then layerthickness measurements were made (Arithmetic Step Height=ASH) with aprofilometer (Dektak 6M; 12.5 μm Stylus), and the results are listed inTable 2.

TABLE 2 Pitch ASH [nm] 10 μm 685 30 μm 100 45 μm 27

By the drop distance alone, the layer thickness can be adjusted in awide range.

EXAMPLE 8 Making an Image and Verifying the Optical Quality after theLamination

Using the ink of Example 5, a portrait of a person was printed onMakrofole® 4-4. The thus produced portrait was laminated together withtransparent Makrofol® 6-2-films at temperatures >180° C., pressures >5bar and times >10 min to form a structure of approx. 800 μm thickness.Light-microscopic investigations before and after the lamination weremade, in order to evaluate the edge definition of individual pixels. Theresults are shown in FIG. 2. There are shown on top in FIG. 2 coloredprinting images (top) and thereunder the same printing images, howeverafter conversion into black & white. On the left side, there is shown adetailed representation of the ink jet printing layer made according tothe invention before the lamination. On the right side, the samedetailed representation is shown after the lamination. It can be seenthat the pixel patterns are maintained also after the lamination innearly the same resolution. The horizontal lines result from theover-lapping sections of the individual ink jet nozzles of the printinghead and have therefore nothing to do with the ink according to theinvention.

Apart from that, an optical investigation of the structure did not showany recognizable phase limit. The structure is a monolithic blockexcellently resisting to delamination.

1. The use of a preparation comprising A) 0.1 to 20 wt % of a bindingagent with a polycarbonate derivative based on a geminally disubstituteddihydroxydiphenyl cycloalkane, B) 30 to 99.9 wt % of a solvent or of amixture of solvents, C) 0 to 10 wt %, referred to dry mass, of a dye orof a mixture of dyes, D) 0 to 10 wt % of a functional material or of amixture of functional materials, E) 0 to 30 wt % of additive and/orauxiliary substances, or of a mixture of such substances, the relativeamounts of the components A) to E) always totaling 100 wt %, as an inkjet printing dye.
 2. The use according to claim 1, wherein thepolycarbonate derivative has an average molecular weight (mean weight)of at least 10,000, preferably from 20,000 to 300,000.
 3. The useaccording to claim 1, wherein the polycarbonate derivative comprisesfunctional carbonate structure units of formula (I),

wherein R¹ and R² are independently from each other hydrogen, halogen,preferably chlorine or bromine, C₁-C₈ alkyl, C₅-C₆ cycloalkyl, C₆-C₁₀aryl, preferably phenyl, and C₇-C₁₂ aralkyl, preferably phenyl-C₁-C₄alkyl, in particular benzyl, m is an integer from 4 to 7, preferably 4or 5, R³ and R⁴ can be individually selected for each X, andindependently represent hydrogen or C₁-C₆ alkyl X is carbon and n is aninteger greater than 20, with the proviso that at least one atom X, R³and R⁴ are both alkyl.
 4. The use according to claim 3, wherein at 1 to2 atoms X, in particular at only one atom X, R³ and R⁴ are both alkyl.5. A method according to claim 3, wherein R³ and R⁴ are methyl.
 6. Theuse according to claim 3, wherein the X atoms in the alpha position tothe diphenyl-substituted C atom (C1) are not dialkyl-substituted.
 7. Theuse according to claim 3, wherein the X atoms in the beta position to C1are disubstituted with alkyl.
 8. The use according to claim 3, wherein mis 4 or
 5. 9. The use according to claim 3, wherein the polycarbonatederivative is based on 4,4′-(3,3,5-trimethyl cyclohexane-1,1-diyl)diphenol, 4,4′-(3,3-dimethyl cyclohexane-1,1-diyl) diphenol, or4,4′-(2,4,4-trimethyl cyclopentane-1,1-diyl) diphenol.
 10. The useaccording to claim 1, wherein the polycarbonate derivative comprises acopolymer in particular consisting of monomer units M1 based on formula(Ib), for instance based on bisphenol A, and monomer units M2 based onthe geminally disubstituted dihydroxydiphenyl cycloalkane, preferably ofthe 4,4′-(3,3,5-trimethyl cyclohexane-1,1-diyl) diphenol, wherein themolar ratio M2/M1 preferably is greater than 0.3, in particular greaterthan 0.4, preferably greater than 0.5.
 11. The use according to claim 1,wherein the component B) is halogen-free.
 12. The use according to claim1, wherein the component B) consists of a liquid aliphatic,cycloaliphatic, and/or aromatic hydrocarbon, a liquid organic ester,and/or of a mixture of such substances.
 13. The use according to claim12, wherein the hydrocarbon and/or the organic ester is selected fromthe group consisting of “mesitylene, 1,2,4-trimethylbenzene, cumene,solvent naphtha, toluene, xylene, methylacetate, ethylacetate,butylacetate, methoxypropylacetate, ethyl-3-ethoxypropionate”.
 14. Theuse according to claim 13, wherein the component B) consists of: L1) 0to 10 wt %, preferably 1 to 5 wt %, in particular 2 to 3 wt %, ofmesitylene, L2) 10 to 50 wt %, preferably 25 to 50 wt %, in particular30 to 40 wt %, of 1-methoxy-2-propanolacetate, L3) 0 to 20 wt %,preferably 1 to 20 wt %, in particular 7 to 15 wt %, of1,2,4-trimethylbenzene, L4) 10 to 50 wt %, preferably 25 to 50 wt %, inparticular 30 to 40 wt %, of ethyl-3-ethoxypropionate, L5) 0 to 10 wt %,preferably 0.01 to 2 wt %, in particular 0.05 to 0.5 wt %, of cumene,and L6) 0 to 80 wt %, preferably 1 to 40 wt %, in particular 15 to 25 wt%, of solvent naphtha, the relative amounts of the components L1 to L6always totaling 100%.
 15. The use according to claim 1, wherein thepreparation comprises: A) 0.1 to 10 wt %, in particular 0.5 to 5 wt %,of a binding agent with a polycarbonate derivative based on a geminallydisubstituted dihydroxydiphenyl cycloalkane, B) 40 to 99.9 wt %, inparticular 45 to 99.5 wt %, of an organic solvent or of a mixture ofsolvents, C) 0.1 to 6 wt %, in particular 0.5 to 4 wt %, of a dye or ofa mixture of dyes, D) 0.001 to 6 wt %, in particular 0.1 to 4 wt %, of afunctional material or of a mixture of functional materials, E) 0.1 to30 wt %, in particular 1 to 20 wt %, of additive and/or auxiliarysubstances, or of a mixture of such substances.
 16. A method for makinga structure with at least a first polymer layer and, optionally, asecond polymer layer, each made from a polycarbonate polymer based onbisphenol A, wherein on the first polymer layer an ink jet printinglayer is arranged, comprising the following steps: a) applying the inkjet printing layer from a preparation according to claim 1 on at leastone partial region of the first polymer layer, b) optionally, drying theink jet printing layer, c) optionally after step a) or step b), placingthe second polymer layer on the first polymer layer, covering the inkjet printing layer, and laminating the first polymer layer and thesecond polymer layer with each other under pressure, at a temperature of120° C. to 230° C. and for a defined time.
 17. The method according toclaim 16, wherein the temperature in step (c) is in the range from 140°C. to 200° C., in particular in the range from 150° C. to 180° C. 18.The method according claim 16, wherein the first polycarbonate layer andthe second polycarbonate layer have a glass temperature Tg of more than145° C.
 19. The method according to claim 16, wherein the thickness ofthe first polycarbonate layer and of the second polycarbonate layer isup to 1,000 μm, in particular from 20 to 200 μm.
 20. The methodaccording to claim 16, wherein the thickness, measured in directionsorthogonal to a main face of a polycarbonate layer, of the ink jetprinting layer is in the range from 0.01 to 10 μm, in particular from0.05 to 5 μm.
 21. A structure obtainable with a method according toclaim
 16. 22. The structure comprising at least a first polycarbonatelayer and an ink jet printing layer from of a preparation according toclaim 1 and arranged on the first polycarbonate layer, whereinoptionally on the side of the printing layer opposite to the firstpolycarbonate layer, a second polycarbonate layer may be arranged. 23.The use of a method according to claim 16 for making a security and/orvalue document, wherein optionally simultaneously with, before or afterthe production of the structure, the first polycarbonate layer and/orthe second polycarbonate layer are directly or indirectly connected in astack with at least one additional layer, for instance a carrier layer.24. The security and/or value document obtainable according to claim 23.25. The security and/or value document comprising a structure accordingto claim
 21. 26. A method for making a structure with at least onepolymer layer and an injection-molded part from a polymer material,wherein between the polymer layer and the injection-molded part an inkjet printing layer is arranged, comprising the following steps: a)applying, on at least one partial region of the polymer layer, the inkjet printing layer from a preparation according to claim 1, b)optionally, drying the ink jet printing layer, c) after step a) or stepb), placing the polymer layer in an injection mold, wherein the ink jetprinting layer showing toward inside, d) injecting into the injectionmold, the polymer material at a temperature of at least 60° C., and e)cooling-off the polymer material to a temperature of at least 20° C.below the temperature of step d), and then taking the structure from theinjection mold.
 27. The method according to claim 26, wherein thetemperature in step d) is in the range from 80° C. to 200° C., inparticular in the range from 100° C. to 180° C., and/or wherein thetemperature in step e) is at least 40° C. below the temperature in stepd).
 28. The method according to claim 26, wherein the polycarbonatelayer has a glass temperature Tg of more than 145° C.
 29. The methodaccording to claim 26, wherein the thickness of the polycarbonate layeris in the range from 10 to 1,000 μm, in particular from 20 to 200 μm.30. The method according to claim 26, wherein the thickness, measured indirections orthogonal to a main face of the polycarbonate layer, of theink jet printing layer is in the range from 0.01 to 10 μm, in particularfrom 0.05 to 5 μm.
 31. The structure obtainable with a method accordingto claim
 26. 32. The structure comprising at least one polycarbonatelayer and an injection-molded part and an ink jet printing layer from apreparation according to claim 1 and arranged between the polycarbonatelayer and the injection-molded part.